8383 research outputs found
Sort by
An alternative pathway for membrane protein biogenesis at the endoplasmic reticulum.
Get PDFFrom Europe PMC via Jisc Publications RouterHistory: epub 2021-07-01, ppub 2021-07-01Publication status: PublishedFunder: Ball State University (Ball State); Grant(s): Provost Startup AwardFunder: Wellcome Trust; Grant(s): 204957/Z/16/ZFunder: NIGMS NIH HHS; Grant(s): R15 GM116032The heterotrimeric Sec61 complex is a major site for the biogenesis of transmembrane proteins (TMPs), accepting nascent TMP precursors that are targeted to the endoplasmic reticulum (ER) by the signal recognition particle (SRP). Unlike most single-spanning membrane proteins, the integration of type III TMPs is completely resistant to small molecule inhibitors of the Sec61 translocon. Using siRNA-mediated depletion of specific ER components, in combination with the potent Sec61 inhibitor ipomoeassin F (Ipom-F), we show that type III TMPs utilise a distinct pathway for membrane integration at the ER. Hence, following SRP-mediated delivery to the ER, type III TMPs can uniquely access the membrane insertase activity of the ER membrane complex (EMC) via a mechanism that is facilitated by the Sec61 translocon. This alternative EMC-mediated insertion pathway allows type III TMPs to bypass the Ipom-F-mediated blockade of membrane integration that is seen with obligate Sec61 clients
Millimeter-Wave Free-Space Dielectric Characterization
Get PDFMillimeter wave technologies have widespread applications, for which dielectric permittivity is a fundamental parameter. The non-resonant free-space measurement techniques for dielectric permittivity using vector network analysis in the millimeter wave range are reviewed. An introductory look at the applications, significance, and properties of dielectric permittivity in the millimeter wave range is addressed first. The principal aspects of free-space millimeter wave measurement methods are then discussed, by assessing a variety of systems, theoretical models, extraction algorithms and calibration methods. In addition to conventional solid dielectric materials, the measurement of artificial metamaterials, liquid, and gaseous-phased samples are separately investigated. The pros of free-space material extraction methods are then compared with resonance and transmission line methods, and their future perspective is presented in the concluding part
Deteriorations in physical qualities during a 10-week unsupervised off-season period in academy rugby union players
Get PDFThis is an Accepted Manuscript of an article published by Taylor & Francis in Science and Medicine in Football on 02/08/2021, available online: https://www.tandfonline.com/doi/abs/10.1080/24733938.2021.1959944Purpose: To determine the changes in physical qualities of academy rugby union players over a 10-week unsupervised off-season period. Methods: Body mass, jump height, sprint performance, and intermittent running (30:15 IFT) of 64 academy rugby union players (age = 17.2 ± 0.4 y) were recorded before and after the off-season. Results: Changes in body mass (+1.4 ± 1.3 kg), countermovement jump (-2.2 ± 1.2 cm), squat jump (-1.5 ± 1.8 cm), 10 m sprint (+0.06 ± 0.05 s), 40 m sprint (+0.13 ± 0.11 s) and 30:15 IFT (-0.8 ± 0.8 kmh-1) were observed (P < 0.001, d = -1.77 to 0.47). Only changes in body mass were greater in forwards than backs (P = 0.036, d = 0.46). Players with higher end-of-season body mass, squat jump and 30:15 IFT had greater off-season changes (P = < 0.001 to 0.044; d = 0.63 to 0.94), whilst the pre-post difference in body mass influenced CMJ (P = 0.005, d = 0.75) and 10 m momentum change (P <0.001, d = 1.61). Conclusion: Understanding the individuality of the changes in physical qualities of academy rugby union players during the off-season is important to ensure players return safely to pre-season training loads
Proton-coupled electron transfer reactivities of electronically divergent heme superoxide intermediates: a kinetic, thermodynamic, and theoretical study.
Get PDFFrom Europe PMC via Jisc Publications RouterHistory: epub 2021-05-27, ppub 2021-07-01Publication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Grant(s): BB/J014478/1Heme superoxides are one of the most versatile metallo-intermediates in biology, and they mediate a vast variety of oxidation and oxygenation reactions involving O2(g). Overall proton-coupled electron transfer (PCET) processes they facilitate may proceed via several different mechanistic pathways, attributes of which are not yet fully understood. Herein we present a detailed investigation into concerted PCET events of a series of geometrically similar, but electronically disparate synthetic heme superoxide mimics, where unprecedented, PCET feasibility-determining electronic effects of the heme center have been identified. These electronic factors firmly modulate both thermodynamic and kinetic parameters that are central to PCET, as supported by our experimental and theoretical observations. Consistently, the most electron-deficient superoxide adduct shows the strongest driving force for PCET, whereas the most electron-rich system remains unreactive. The pivotal role of these findings in understanding significant heme systems in biology, as well as in alternative energy applications is also discussed
Experiences of international students studying in a UK university: how do international students studying in the UK’s Higher Education sector build academic resilience?
Get PDFWith the ever-increasing number of international students entering the global market, many of which enrol on post-graduate Higher Education (HE) programmes in the UK, current research offers limited insight into the key role academic resilience plays in enabling international cohorts’ progression and achievement. This study aims to fill the gap by investigating how international students studying in the UK build academic resilience, contributing to the literature and informing governmental policies and university practices. Guided by Bourdieu’s seminal concepts of social capital generation and conversion, this work develops the theories of other researchers in building capital to enhance the academic resilience of students. It achieves this by adopting a qualitative interpretivist paradigm aligned to similar studies, using a longitudinal representative case study in the UK. Over a period of 42-months, 36 respondents formed four non-probability samples. Data was collected using semi-structured interviews, a focus group and questionnaire, the findings of which were analysed using grounded theory methods and supported by computer-aided qualitative analysis software. The results identify six prevalent capitals that students either generate prior to their arrival in the UK or are socially constructed with newly formed peer-groups. Notably, the emergence of neo-familial capital akin to concepts of fictive kinship offers a fresh perspective on the need to formally address the importance academic resilience has on the international student’s learning experience and progression. The findings provide insight into the sources of international students’ academic resilience and how these can change over space and time. This insight offers universities with theoretical and practical guidance on the need to embed proactive student support systems that stimulate academic resilience amongst its international students. It also informs governmental policies on attracting students from overseas as it seeks to enhance the UK’s HE offer to global markets
Verification and refutation of C programs based on k -induction and invariant inference
Get PDFFrom Springer Nature via Jisc Publications RouterHistory: registration 2020-04-23, online 2020-05-18, pub-electronic 2020-05-18, pub-print 2021-04Publication status: PublishedFunder: University of ManchesterAbstract: DepthK is a source-to-source transformation tool that employs bounded model checking (BMC) to verify and falsify safety properties in single- and multi-threaded C programs, without manual annotation of loop invariants. Here, we describe and evaluate a proof-by-induction algorithm that combines k-induction with invariant inference to prove and refute safety properties. We apply two invariant generators to produce program invariants and feed these into a k-induction-based verification algorithm implemented in DepthK, which uses the efficient SMT-based context-bounded model checker (ESBMC) as sequential verification back-end. A set of C benchmarks from the International Competition on Software Verification (SV-COMP) and embedded-system applications extracted from the available literature are used to evaluate the effectiveness of the proposed approach. Experimental results show that k-induction with invariants can handle a wide variety of safety properties, in typical programs with loops and embedded software applications from the telecommunications, control systems, and medical domains. The results of our comparative evaluation extend the knowledge about approaches that rely on both BMC and k-induction for software verification, in the following ways. (1) The proposed method outperforms the existing implementations that use k-induction with an interval-invariant generator (e.g., 2LS and ESBMC), in the category ConcurrencySafety, and overcame, in others categories, such as SoftwareSystems, other software verifiers that use plain BMC (e.g., CBMC). Also, (2) it is more precise than other verifiers based on the property-directed reachability (PDR) algorithm (i.e., SeaHorn, Vvt and CPAchecker-CTIGAR). This way, our methodology demonstrated improvement over existing BMC and k-induction-based approaches
The Relationship between Body Mass Index and Mammographic Density during a Premenopausal Weight Loss Intervention Study
Get PDFFrom MDPI via Jisc Publications RouterHistory: accepted 2021-06-18, pub-electronic 2021-06-29Publication status: PublishedFunder: Cancer Research UK; Grant(s): C569/A16891, IS-BRC-1215-20007We evaluated the association between short-term change in body mass index (BMI) and breast density during a 1 year weight-loss intervention (Manchester, UK). We included 65 premenopausal women (35–45 years, ≥7 kg adult weight gain, family history of breast cancer). BMI and breast density (semi-automated area-based, automated volume-based) were measured at baseline, 1 year, and 2 years after study entry (1 year post intervention). Cross-sectional (between-women) and short-term change (within-women) associations between BMI and breast density were measured using repeated-measures correlation coefficients and multivariable linear mixed models. BMI was positively correlated with dense volume between-women (r = 0.41, 95%CI: 0.17, 0.61), but less so within-women (r = 0.08, 95%CI: −0.16, 0.28). There was little association with dense area (between-women r = −0.12, 95%CI: −0.38, 0.16; within-women r = 0.01, 95%CI: −0.24, 0.25). BMI and breast fat were positively correlated (volume: between r = 0.77, 95%CI: 0.69, 0.84, within r = 0.58, 95%CI: 0.36, 0.75; area: between r = 0.74, 95%CI: 0.63, 0.82, within r = 0.45, 95%CI: 0.23, 0.63). Multivariable models reported similar associations. Exploratory analysis suggested associations between BMI gain from 20 years and density measures (standard deviation change per +5 kg/m2 BMI: dense area: +0.61 (95%CI: 0.12, 1.09); fat volume: −0.31 (95%CI: −0.62, 0.00)). Short-term BMI change is likely to be positively associated with breast fat, but we found little association with dense tissue, although power was limited by small sample size
Extrinsic and Existential Mortality Risk in Reproductive Decision-Making: Examining the Effects of COVID-19 Experience and Climate Change Beliefs
Get PDFWhile the COVID-19 pandemic has presented an immediate risk to human life around the world, climate change poses an arguably greater—although less immediate—threat to our species’ survival. Within the framework of life-history theory (LHT), this pre-registered study investigated whether extrinsic risk (i.e., external factors that pose a risk to an individual’s life, e.g., COVID-19) and existential risk (i.e., risks with outcomes that threaten the existence of humans as a species, e.g., climate change) had similar or different relationships with reproductive decision-making. A UK representative sample of 325 participants between 18 and 35 years of age was asked to indicate their ideal number of children, ideal age to start having children, and whether their desire for a child had recently changed. Participants were asked about their experiences of COVID-19 and given a series of scales with which to assess their beliefs about climate change. In support of LHT, the study found evidence that knowing people who had been hospitalized with or died of COVID-19 was associated with a greater ideal number of children. Conversely, there was no clear evidence of a relationship between climate change beliefs and reproductive decision-making. The repercussions for understanding how we interpret and respond to different forms of mortality risk are discussed
Women who remain in relationships with registered sexual offenders: Analysis of forum discussion
Get PDFFrom Wiley via Jisc Publications RouterHistory: received 2020-09-25, rev-recd 2021-06-08, accepted 2021-06-09, pub-electronic 2021-07-08Article version: VoRPublication status: PublishedAbstract: Registered sexual offenders (RSOs) are inevitably on the receiving end of much negative evaluation within society. By association, individuals in close relationships with RSOs may experience what Goffman (1963) [Stigma: Notes on the management of spoiled identity. Simon & Schuster Ltd.] termed ‘courtesy stigma’, through which they are also negatively evaluated. The present study explores this phenomenon in the contemporary context of online discussion. Drawing on recent methodological developments in the microanalysis of online data, three specific threads from online parenting forums are examined, each opening with a specific account of their dilemma by women in intimate relationships with RSOs. Analysis of the sequential interaction within each thread demonstrates the way that stigma is performed by online parenting communities and how individuals manage that stigma as the interaction unfolds. We conclude that partners of RSOs, unlike family members, can mitigate courtesy stigma by ending the relationship, but otherwise risk being ostracised by community members
New Self-dual Codes from 2 x 2 block circulant matrices, Group Rings and Neighbours of Neighbours
Get PDFThis document is the Accepted Manuscript version of a published work that appeared in final form in Advances in Mathematics of Communications. To access the final edited and published work see https://www.aimsciences.org//article/doi/10.3934/amc.2021039http://dx.doi.org/10.3934/amc.2021039In this paper, we construct new self-dual codes from a construction that involves a unique combination; 2 x 2 block circulant matrices, group rings and a reverse circulant matrix. There are certain conditions, specified in this paper, where this new construction yields self-dual codes. The theory is supported by the construction of self-dual codes over the rings F2, F2+uF2 and F4+uF4. Using extensions and neighbours of codes, we construct 32 new self-dual codes of length 68. We construct 48 new best known singly-even self-dual codes of length 96
Data sources:
Access Repository Dashboard
Do you manage ChesterRep? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!